Suction lipectomy or lipolysis is a surgical procedure for removing fatty tissue and fatty tumors from localized areas of the human body through small incisions that can be easily concealed. The surgical procedure customarily employed requires an incision in the skin to expose the fatty tissue. The tip of a cannula is then inserted into the incision and manually directed by the surgeon towards the desired area of the body. By guiding the tip through the fatty tissue while simultaneously applying suction through a longitudinal passage extending through the cannula in communication with the tip, fat is surgically aspirated from the body. For adequate aspiration, approximately 15-20 strokes of the tip through the fatty tissue are often necessary.
FIG. 1 is an illustration of a conventional cannula 10 used for suction lipectomy having a tip 12 and a handle 14 formed at opposite ends thereof. Tip 10 has a hole 16 communicating with a central longitudinal passage 19 extending through the cannula for connection to a suction means 20 in a well known manner. To remove a desired amount of fat from fatty tissue 22 (see FIGS. 2 and 3), an incision 24 is first made in skin 26 to expose the tissue. Tip 10 is then inserted through incision 24 into tissue 26. By gripping handle 14 to move tip 12 through the fatty tissue in continuous reciprocating strokes (see arrows A and A') while applying suction, fat is surgically aspirated through hole 16 and passage 18. After a sufficient number of strokes by the surgeon, the original thickness T of fatty tissue is reduced to a lesser thickness T' (see FIG. 3A).
Because suction lipectomy is essentially cosmetic surgery, considerable surgical skill is necessary to repetitively guide tip 12 in directions A, A' to leave an even layer of tissue intact. This requires guiding tip 12 at a constant depth beneath the skin. Otherwise, different thicknesses of remaining tissue will cause permanent indentations 28 to appear in the skin following surgery (see FIG. 3A), which can be very unslightly. Unfortunately, however, the results frequently obtained with suction lipectomy are of the type shown in FIG. 3A, since the surgeon does not always know or cannot maintain the precise depth at which he guides tip 12 through the tissue. Further, since the surgeon must guide the tip in directions A,A', there is a tendency during the stroke to rotate (arrows B,B') the cannula about its longitudinal axis, causing hole 16 to move above or below the desired depth. Even if the surgeon possesses sufficient skill to guide tip 12 at constant depth, the large number of repetitive strokes necessary for adequate aspiration renders the surgical procedure fatiguing to the surgeon, possibly resulting in momentary loss of control while guiding the cannula.
To remove these permanent indentations 28 or wavy appearance in the skin frequency caused by use of conventional cannula 10, surgeons generally rely upon secondary surgery (i.e., suction lipectomy) to remove additional fatty tissue. Indeed, clinical observations reveal that secondary surgical procedures are employed on approximately 20-26% of patients initially undergoing suction lipectomy.
To avoid the foregoing problems and reduce the incidence of secondary surgery, my co-pending U.S. patent application, Ser. No. 651,720, filed Sept. 18, 1984, discloses a conventional cannula 10 including a parallel guide bar mounted thereon having a forward guide surface pressed by the surgeon into constant contact with the skin so that the suction hole remains at constant depth during reciprocation of the cannula through the fatty tissue. The guide bar, preferably formed of medical grade stainless steel, is connected at a rear end thereof to the cannula with a threaded bolt secured to the handle and a rear hinge fixing the guide bar to the handle. The guide bar includes a major elevated portion offset from forward and rear ends of the guide bar in a direction away from the cannula. By providing the elevated portion upon the guide bar, the surgeon is able to grip the elevated portion to facilitate reciprocating movement of the cannula through the fatty tissue and maintain the guide surface in contact with the skin when performing the surgical procedure on various parts and therefore different contours of the body (i.e., concave, convex or flat).
Friction between the guide surface and the skin surface tends to be minimized by providing a pair of wheels mounted to the guide bar tip with a cross bolt and nut. The wheels rotate freely on the bolt to provide tangential rolling contact with the skin surface for low friction movement during reciprocating strokes with the cannula.
Adjustment of the distance between the cannula and wheels is achieved by manipulation of nuts on the handle bolt to pivot the guide wheels towards or away from the cannula about the hinge. This bolt and hinge mechanism constitutes an improvement over the dual bolt mechanism disclosed in my prior co-pending patent application, Ser. No. 607,714, filed May 7, 1984, wherein spacing between the guide bar and cannula was achieved by adjustment of nuts provided upon both bolts.
In my prior invention described supra, it is necessary to modify the structure of the cannula handle to include a threaded hole accomodating the bolt and a post upon which the hinge is mounted. However, since conventional cannulas and handles thereof are not equipped with the above features, relatively expensive retro-fitting is required to machine and tap a threaded hole for receiving the bolt and to provide a mounting post for the hinge.
It is accordingly an object of the present invention to provide an improved guide bar structure connectible to a conventional cannula without requiring alteration of the cannula handle to mount the guide bar thereon.
Another object of the invention is to provide a guide bar that can be universally fitted to any type of cannula.
Still a further object is to provide a guide bar that is simple in design and economical to manufacture.
Still another object is to provide a guide bar structure which, when attached to a cannula, allows the cannula to be easily guided by the surgeon at constant depth so that a desired amount of fatty tissue is surgically aspirated while leaving an even thickness layer of tissue intact.
The wheels in my prior invention are generally parallel to each other and include peripheral surfaces in constant contact with the skin during reciprocation of the cannula by the surgeon. One of the problems with this arrangement is that the skin between the wheels and underlying cannula and soft fatty tissue immediately beneath the skin surface may sometimes bunch up beneath the wheels. This causes the wheels to become temporarily elevated in a localized area relative to the skin surface. This temporary elevation of the wheels causes a corresponding reduction in depth through which the cannula tip moves through fatty tissue possibly resulting in wavy indentations 28 to appear in the skin after the suction lipectomy procedure.
It is accordingly another object of the present invention to provide an improved guide wheel structure capable of stretching and stabilizing the skin between the wheels and underlying cannula to prevent localized changes of the elevation of the wheels relative to skin surface outwardly adjacent the wheels during reciprocating movement of the cannula.
Another object is to provide a guide bar having an adjustment mechanism for varying the distance between the cannula tip and guide wheels independent of the cannula handle.